package com.hmdp.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.time.LocalDateTime;
import java.util.concurrent.TimeUnit;

/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Autowired
    private StringRedisTemplate redisTemplate;

    @Autowired
    private RedisIdWorker redisIdWorker;

    @Autowired
    private ISeckillVoucherService seckillVoucherService;

    @Autowired
    private RedissonClient redissonClient ;

    @Override
    public Result seckillVoucher(Long voucherId) throws InterruptedException {


        //1. 查询优惠券
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);

        //2.判断秒杀是否开始
        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
            return Result.fail("秒杀尚未开始");
        }

        //3. 判断秒杀是否已经结束
        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
            return Result.fail("秒杀已经结束");
        }
        //4. 判断库存是否充足
        if (voucher.getStock() < 1) {
            return Result.fail("库存不足");
        }

        Long userId = UserHolder.getUser().getId();
        // 加锁
        //synchronized (userId.toString().intern()) {

        // 创建锁对象
        // SimpleRedisLock redisLock = new SimpleRedisLock(redisTemplate, "order:" + userId);

        // 获取锁 （可重入） 指定锁的名称
        RLock redisLock = redissonClient.getLock("lock:order:" + userId);

        // 尝试获取锁
        // boolean isLock = redisLock.tryLock(30);

        // 尝试获取锁，参数分别是： 获取锁的最大等待时间（期间会重试），锁自动释放时间，时间单位
        boolean isLock = redisLock.tryLock(1, TimeUnit.SECONDS);
        // 判断是否获取锁成功
        if (!isLock) {
            return Result.fail("一个用户不允许重复下单");
        }

        try {
            // 获取代理对象（事务）
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();

            return proxy.createVoucherOrder(voucherId);

        }finally {
            // 释放锁
            redisLock.unlock();
        }
    }

    @Transactional
    public Result createVoucherOrder(Long voucherId) {

        // 6 一人一单
        Long userId = UserHolder.getUser().getId();
        // 6.1 查询订单
        Integer count = query().eq("user_id", userId)
                .eq("voucher_id", voucherId).count();
        // 6.2 判断库存是否存在
        if (count > 0) {
            return Result.fail("用户已经购买过一次！");
        }

        //5. 扣减库存
        boolean success = seckillVoucherService.update().setSql(" stock = stock -1 ")
                .eq(" voucher_id", voucherId)
                .gt("stock", 0) // 乐观锁方案
                .update();
        if (!success) {
            // 扣减失败
            return Result.fail("库存不足");
        }


        //6. 创建订单
        VoucherOrder voucherOrder = new VoucherOrder();
        // 6.1 订单id
        Long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);
        // 6.2 用户id
        UserDTO user = UserHolder.getUser();
        voucherOrder.setUserId(user.getId());
        // 6.3 代金券的id
        voucherOrder.setVoucherId(voucherId);
        //7. 返回订单id
        save(voucherOrder);


        return Result.ok(voucherId);
    }
}
